酶解反应和膜分离耦合制备乳源抗菌肽

Preparation of antibacterial peptides by integration of enzymatic hydrolysis and membrane separation from milk protein

采用间歇式酶膜反应工艺水解牛乳蛋白制备抗菌肽,以金黄色葡萄球菌做指示菌,考察了酶膜耦合时间、底物浓度、加酶量、温度、pH值和出肽速率等因素对蛋白转化率的影响,并在单因素影响实验的基础上,通过正交实验进行工艺优化.结果表明:间歇式酶膜反应的最优工艺参数为耦合时间120 min,底物浓度2%,加酶量3%,温度30℃,pH7.5,出肽速率6 mL/min;在此优化条件下,蛋白转化率为0.293%,牛乳蛋白酶解产物的最小抑菌浓度为4.8μg/mL.该法通过消除产物抑制效应,有效地避免多肽过度降解,从而提高产物活性,较好地强化了反应过程,为酶法制备乳源抗菌肽提供一种更有效的方法.

Antibacterial peptides were prepared from milk protein by batch enzyme membrane reaction.Effects of coupling time,substrate concentration,enzyme-substrate ratio,hydrolysis temperature,pH and peptides flux on the conversion of milk protein,in which Staphylococcus aureus was used as indicator bacteria,were determined.Optimal parameters for batch enzyme membrane reaction were established by single factor and orthogonal test.The results show that the optimum preparation conditions are as follows： coupling time 120 min,substrate concentration 2 %,enzyme-substrate ratio 3 %,reaction temperature 30 ℃,pH 7.5 and peptides flux 6 mL/min.Under these conditions,the conversion rate of milk protein is 0.293 %,and the minimum inhibitory concentration（MIC） of hydrolysates obtained from milk protein is 4.8 μg/mL against Staphylococcus aureus.The results also show that this method can reduce the inhibition effect of products,and over-degradation of peptide is avoided effectively by online separation of product.Furthermore,it can promote the products activity and strengthen the reaction process.Therefore,the batch enzyme membrane reaction provides a more efficient way to prepare antibacterial peptides from milk protein.